| Abstract: | The distribution of labeled cyanocobalamin (CN-57Co]Cbl = 57Co]-vitamin B12) in pleurocercoids and adult tapeworms of Spirometra mansonoides was studied during development in mice 22 days days PI, respectively. Plerocercoid scolices, obtained by cutting away their bodies or by in vitro enzymatic dissolution of the bodies, were pulsed with CN- magnitude of 57Co Cbl for 1h at 37 degrees C and reimplanted subcutaneously into mice or given per os to cats. In regenerated plerocercoids, the highest concentration of magnitude of 57Co Cbl occurred in the scolex and then decreased posteriorly in the newly-formed tissues of the body. Approximately 60% of the total magnitude of 57Co Cbl present remained concentrated in the scolex following body regeneration plerocercoids and adult tapeworms of Spirometra mansonoides was studied during development in mice 22 days post-infection (PI) and in cats 16 days PI, respectively. Plerocercoid scolices, obtained by cutting away their bodies or by in vitro enzymatic dissolution of the bodies, were pulsed with CN-57Co]Cbl for 1 h at 37 degrees C and reimplanted subcutaneously into mice or given per os to cats. In regenerated plerocercoids, the highest concentration of 57Co]Cbl occurred in the scolex and then decreased posteriorly in the newly-formed tissues of the body. Approximately 60% of the total 57Co]Cbl present remained concentrated in the scolex following body regeneration for up to 109 days PI. This high 57Co]Cbl concentration in the plerocercoid scolex was bound to protein and appears to be maintained by a complex homeostatic mechanism in association with directional transport of 57Co]Cbl to the scolex with ultimate depletion along the length of the body.(ABSTRACT TRUNCATED AT 250 WORDS) |
